(19) |
 |
|
(11) |
EP 0 741 159 A3 |
(12) |
EUROPEAN PATENT APPLICATION |
(88) |
Date of publication A3: |
|
01.10.1997 Bulletin 1997/40 |
(43) |
Date of publication A2: |
|
06.11.1996 Bulletin 1996/45 |
(22) |
Date of filing: 02.05.1996 |
|
|
(84) |
Designated Contracting States: |
|
DE FR GB IT |
(30) |
Priority: |
03.05.1995 US 433181
|
(71) |
Applicant: DOW CORNING CORPORATION |
|
Midland,
Michigan 48686-0994 (US) |
|
(72) |
Inventors: |
|
- Biggs, Timothy Nolen
Midland,
Michigan 48640 (US)
- Legrow, Gary Edward
Midland,
Michigan 48642 (US)
|
(74) |
Representative: Lewin, John Harvey |
|
Elkington and Fife,
Prospect House,
8 Pembroke Road Sevenoaks,
Kent TN13 1XR Sevenoaks,
Kent TN13 1XR (GB) |
|
|
|
(54) |
Methods of making polysiloxanes |
(57) Linear or straight-chain trimethylsiloxy endcapped methylhydrogen polysiloxanes are
made by contacting hexamethyldisiloxane with a highly pure methylhydrogen cyclic siloxane,
in the presence of anhydrous trifluoromethane sulfonic acid catalyst at room temperature.
Trimethylsiloxy endcapped alkylmethyl siloxanes are made by reacting the linear or
straight-chain trimethylsiloxy endcapped methylhydrogen polysiloxanes with an alpha-olefin,
in the presence of a platinum catalyst. Alkylmethyl cyclic siloxanes containing zero
parts per million residual ≡SiH, are made by reacting anhydrous alpha-olefins and
a highly pure methylhydrogen cyclic siloxane, in the presence of dried platinum catalyst
supported on carbon particles.